This invention relates to a method and apparatus for monitoring and assessing the radiation emanated by a body undergoing test, such as, cardiac function monitoring and assessment, and more particularly, to a non-invasive system for determining the condition of the functioning of a patient's heart, and to a novel ejection fraction meter.
The use of radionuclide tracers and gamma radiation detectors to monitor cardiac function by gated blood pool volume measurement, is now generally well known and practiced in the field of nuclear medicine. Such a non-invasive system for monitoring and evaluating cardiac function is disclosed for example, in U.S. Pat. No. 5,072,458, which is a continuation-in-part of Ser. No. 07/096,521, filed Sep. 15, 1987, U.S. Pat. No. 5,007,427, which is a continuation-in-part of Ser. No. 07/046,854, filed May 7, 1987, U.S. Pat. No. 4,920,969, which is a division of Ser. No. 06/785,549, filed Oct. 8, 1985, now abandoned. According to the disclosure in this patent, an ambulatory nuclear detector has a physiological monitoring system associated therewith for evaluation of heart function by measurement of cardiac stroke volume relative to end diastolic volume, generally known as ejection fraction, deemed to be the best indicator of heart condition or cardiac function by non-invasive measurement means.
According to such prior systems for monitoring and evaluating cardiac function, in a non-invasive manner, intermittent readouts of ejection fraction is obtained by sampled measurements derived from an array of radiation detectors. Accordingly, the readout data on ejection fraction from such prior systems is in a converted digital format. Such prior systems for monitoring and evaluating cardiac function are sometime limited in use because of hardware complexities associated with data processing and data storage operations heretofore deemed necessary to obtain accurate data readout. Continuous, real time assessment of cardiac function with the desired degree of data accuracy has not, therefore, been available from non-invasive types of cardiac monitoring systems.
In addition to monitoring a body to determine cardiac function using tracers and gamma radiation detectors, there are similar situations regarding the measuring and testing of other bodies, such as therapeutic radionuclides, particularly, seeds used for implantation in prostate cancer and breast cancer, as well as possibly for removal of fat and plaque in cardiovascular disease. In one example, I-125 seeds for implantation are tested for asymmetry. The asymmetry or degree of same of such seed bodies is important information. Prior systems for developing such information are complex, and it is difficult to obtain accurate readout data by known prior art systems.
It is therefore an important object of the present invention to provide a method and apparatus for monitoring and evaluating a body undergoing test in a non-invasive manner on a continuous and real time basis.
A further object of the present invention is to provide a method and apparatus for monitoring and assessing cardiac function on a continuous and real time basis by readout of ejection fraction as an index or indicator of a patient's heart condition.
A still further object of the present invention is to provide a method and apparatus for monitoring and assessing therapeutic radionuclides to determine a property thereof, such as, asymmetry.
Another object of the present invention is to provide a novel efficacious ejection fraction meter.